Presently knitting patterns for use on flat-bed knitting machines or circular knitting machines are drafted on the monitor or screen of a so-called VDU (video display unit). In such a VDU comprising a device of the type mentioned above, the knitting pattern is drafted on the monitor with the aid of an input device in the form of a keyboard and is stored in the image memory after completion. It is necessary for the purpose of as exact a reproduction of the form and proportions of the loops as possible as well as for an approximation of the three-dimensional cut and shape of the knitted fabric as it is being worn, to be able to stretch parts of the loops of a knitting pattern in different ways. While, in the latter case, this depends on the three-dimensional shape of the knitted fabric as it is being worn, for the proportions of the individual loops it depends on the fineness of the machine, the thickness of the yarn, the closeness, the type of knit, the casting off of the goods and the like or it is determined by these factors.
For example, the stretching of loops has up to now been done by displaying or storing each loop by a plurality of image points on the monitor or memory points in the image memory. If, for example, for displaying a loop a ratio of three image points in a horizontal direction and five image points in a vertical direction on the monitor is selected, this one loop is stored in the image memory in three times five, i.e., fifteen memory locations. This requires, on the one hand, a relatively large image memory and, on the other hand, a relatively complicated input procedure. If such a knitting pattern, at first only available as a draft, is to be changed, this is relatively complicated if the proportion of loops is to be changed in particular areas or overall, because it is necessary to change each individual loop, i.e., the fifteen image points or memory locations. This not only entails considerable effort but also the time needed for this plays a relatively important role. It is necessary to reprogram the entire image memory with these new proportions or dimensions of the individual loops. The knitting pattern is maintained in the image memory as a true representation and the depiction or display on the monitor is an exact reproduction of the contents of the memory.